Magnetism And Matter — Physics STD 12 Science — Question

The electric field intensity produced by the radiations coming from 100W bulb at a 3 m distance is E. The electric field intensity produced by the radiations coming from 50W bulb at the same distance is:

A signal emitted by an antenna from a certain point can be received at another point of the surface in the form of(a) Sky wave(b) Ground wave(c) Sea wave(d) Both (a) and (b)

At room temperature, a P-type semiconductor has(a) Large number of holes and few electrons(b) Large number of free electrons and few holes(c) Equal number of free electrons and holes(d) No electrons or holes

If in nature there may not be an element for which the principal quantum number n > 4, then the total possible number of elements will be(a) 60(b) 32(c) 4(d) 64

The coil of dynamo is rotating in a magnetic field. The developed induced e.m.f. changes and the number of magnetic lines of force also changes. Which of the following condition is correct(a) Lines of force minimum but induced e.m.f. is zero(b) Lines of force maximum but induced e.m.f. is zero(c) Lines of force maximum but induced e.m.f. is not zero(d) Lines of force maximum but induced e.m.f. is also maximum

The light rays having photons of energy 1.8 eV are falling on a metal surface having a work function 1.2 eV. What is the stopping potential to be applied to stop the emitting electrons(a) 3 eV(b) 1.2 eV(c) 0.6 eV  (d) 1.4 eV

Two equal and opposite charges of 5 coulomb are kept mutually at a distance of 5.0 cm. The electric dipole moment of the system is :

The electric field and the electric potential at a point are E and V respectively.